Method for manufacturing semiconductor chips from a semiconductor wafer

ABSTRACT

A method for manufacturing semiconductor chips from a semiconductor wafer, including the steps of: fastening, on a first support frame, a second support frame having outer dimensions smaller than the outer dimensions of the first frame and greater than the inner dimensions of the first frame; arranging the wafer on a surface of a film stretched on the second frame; carrying out wafer processing operations by using equipment capable of receiving the first frame; separating the second frame from the first frame and removing the first frame; and carrying out wafer processing operations by using equipment capable of receiving the second frame.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/153,959, filed Jun. 6, 2011, which claims thepriority benefit of French patent application number 10/54472, filed onJun. 8, 2010, entitled “METHOD FOR MANUFACTURING SEMICONDUCTOR CHIPSFROM A SEMICONDUCTOR OR WAFER,” which is hereby incorporated byreference to the maximum extent allowable by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturingsemiconductor chips from a semiconductor wafer.

2. Discussion of the Related Art

The manufacturing of semiconductor chips especially comprises stepsduring which components and interconnect metallizations are formedinside and on top of a semiconductor wafer, followed by a step duringwhich the wafer is cut into individual chips, for example, by means of asaw. Various individual chip testing steps are generally provided afterthe cutting.

FIGS. 1A, 1B and 2A, 2B schematically illustrate steps of a method forcutting a semiconductor wafer 10 into individual chips by means of asaw. FIGS. 1A and 2A are top views and FIGS. 1B and 2B respectively arecross-section views along planes B-B of FIGS. 1A and 2A.

FIGS. 1A and 1B illustrate an initial step in which wafer 10 is arrangedon a surface of an adhesive film 12 stretched on a support frame 14.Generally, wafer 10 has an approximately round shape and frame 14 has around inner contour with a diameter greater than the diameter of wafer10. In this example, the outer contour of frame 14 has a generallyapproximately square shape with rounded corners and comprises locationnotches 16.

The specific shape of frame 14, and more specifically of its outercontour, enables to accurately position the wafer in a processingmachine, for example, a sawing machine. In a given production line,frame 14 generally is an element of standard shape and dimension, usedat various steps of the manufacturing during which the wafer should bemaintained on a support. Thus, the various machines of a givenmanufacturing line are provided to receive a type of support frame 14,of given shape and dimensions.

FIGS. 2A and 2B illustrate the actual operation of cutting of wafer 10into individual chips 18. The cutting is conventionally performed bymeans of a circular saw (not shown) running through the wafer along agrid of lines and columns. The cutting is performed across the entirethickness of the wafer and stops in the upper portion of adhesive film12, without however cutting this film. It should be noted that, inpractice, a semiconductor wafer comprises a much greater number ofelementary chips 18 than what has been shown. It should be noted thatgenerally, the semiconductor wafer is not perfectly circular but has aflat side, not shown, enabling to align all wafers in the same way withrespect to frame 14.

After the wafer has been cut, the individual chips remain on frame 14,and other manufacturing steps may be provided, during which the cutwafer is processed in machines capable of receiving frame 14. Such stepsfor example are a visual inspection of the chips, a probe test, amarking of defective chips, etc. Adhesive film 12 especially enableschips 18 to remain in place during these steps and during subsequenttransportations of frame 14.

In some cases, the user or the customer desires to receive the cut chipsto assemble them in various electronic devices. The chips are thenshipped on the support frame 14 on which they have been cut. Onreception of the chips, the test and/or inspection steps may beimplemented again by using equipment capable of receiving frame 14. Theactual mounting of the chips, for example, their mounting on printedcircuit boards, is also carried out by means of machines capable ofreceiving frame 14.

The different manufacturers and users of semiconductor chips do notnecessarily use the same support frame standards. Now, generally, givenequipment is equipped to receive frames of a single standard.Accordingly, in such a production system, a manufacturer ofsemiconductor chips using a given type of frame can only sell hisproduction to users equipped to receive this type of frame.

FIGS. 3 and 4 are top views schematically showing, respectively, a frame34 and a frame 44, corresponding to two standards much used in the artto support wafers having a 20-cm diameter (approximately 8 inches), thatis, standard FF-108 and standard FF-105. Frames 34 and 44 haveapproximately identical general shapes but different dimensions. Thegeneral shapes of frames 34 and 44 are similar. Frame 44 has dimensionsslightly smaller than the dimensions of frame 34, and in particularouter dimensions smaller than the outer dimensions of frame 34 butgreater than the inner diameter of frame 34. In this example, the innerdiameter of frame 44 is slightly smaller than the inner diameter offrame 34. The difference in outer dimensions especially results in thatthe machines capable of receiving frame 34 are not capable of receivingframe 44, and conversely.

It would be desirable for a manufacturer having equipment capable ofreceiving frame 34 to be able to sell his production to a user havingequipment capable of receiving frame 44 (smaller than frame 34) withoutfor one or the other of the manufacturer and of the user to have tomodify his machines.

SUMMARY OF THE INVENTION

Thus, an embodiment provides a method for manufacturing semiconductorchips from a semiconductor wafer, which overcomes at least some of thedisadvantages of existing methods.

An embodiment provides such a method capable of producing, in aproduction line capable of processing semiconductor wafers arranged on aframe of a first type, semiconductor chips arranged on a support frameof a second type having smaller outer dimensions than the frame of thefirst type.

An embodiment provides such a method which is easy to implement.

Thus, an embodiment provides a method for manufacturing semiconductorchips from a semiconductor wafer, comprising the steps of: fastening, ona first support frame, a second support frame having outer dimensionssmaller than the outer dimensions of the first frame and greater thanthe inner dimensions of the first frame; arranging the wafer on asurface of a film stretched on the second frame; carrying out waferprocessing operations by using equipment capable of receiving the firstframe; separating the second frame from the first frame and removing thefirst frame; and carrying out wafer processing operations by usingequipment capable of receiving the second frame.

According to an embodiment, the processing operations in equipmentcompatible with the first frame comprise a step during which the waferis cut into semiconductor chips and at least one semiconductor chip teststep.

According to an embodiment, the processing operations in equipmentcompatible with the second frame comprise a step of assembly of thesemiconductor chips in electronic devices.

According to an embodiment, the first frame comprises, on the side of asurface, guiding and fastening means capable of receiving the secondframe, these means being contained, in top view, within the outercontour of the first frame.

According to an embodiment, the outer and inner contours of the firstframe respectively have a square general shape with rounded corners anda circular shape.

According to an embodiment, the guiding and fastening means comprise:three guide rails fastened in the vicinity of three sides of the squareforming the outer contour of the first frame, these guide railsdelimiting a space inside of which the second frame is capable of beinginserted; and a removable lug capable of being fastened in the vicinityof the fourth side of the square forming the outer contour of the firstframe.

According to an embodiment, the step during which the second frame isfastened to the first frame comprises the operations of: removing theremovable lug from the first frame; inserting the second frame betweenthe guide rails of the first frame; and fastening the removable lug tothe first frame.

According to an embodiment, the separation step comprises the operationsof: removing the removable lug from the first frame; and removing thesecond frame from the guide rails of the first frame.

Another embodiment provides a support frame for a semiconductor wafer,comprising, on the side of a surface, fastening means capable ofreceiving a second frame of outer dimensions respectively smaller thanand greater than the outer and inner dimensions of the support frame,these means being contained, in top view, within the outer contour ofthe support frame.

According to an embodiment, this support frame has an outer contour ofgenerally square shape with rounded corners and a circular innercontour, said means comprising: three guide rails fastened in thevicinity of three sides of the square forming the outer contour of thesupport frame, these guide rails delimiting a space inside of which thesecond frame is capable of being inserted; and a removable lug capableof being fastened in the vicinity of the fourth side of the supportframe.

The foregoing and other objects, features, and advantages will bediscussed in detail in the following non-limiting description ofspecific embodiments in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 2A, 2B, previously described, schematically illustratesteps of a conventional method for cutting a semiconductor wafer intoindividual chips by means of a saw;

FIG. 3, previously described, is a top view schematically showing anexample of a first type of semiconductor wafer support frame;

FIG. 4, previously described, is a top view schematically showing anexample of a second type of a semiconductor wafer support frame, ofdimensions smaller than the dimensions of the support frame of FIG. 3;and

FIGS. 5A, 5B, 5C, 6A, 6B, 7A, 7B, and 8A, 8B schematically illustratesteps of a method for manufacturing semiconductor chips, capable ofproducing, in a production line to specifically adapted to processsemiconductor wafers arranged on a first frame, chips arranged onanother frame of smaller outer dimensions.

DETAILED DESCRIPTION

For clarity, the same elements have been designated with the samereference numerals in the different drawings and, further, the variousdrawings are not to scale.

FIGS. 5A, 5B, 5C, 6A, 6B, 7A, 7B, and 8A, 8B schematically illustratesteps of a method for manufacturing semiconductor chips, capable ofproducing, in a production line specifically adapted to processsemiconductor wafers arranged on a frame 34 of the type described inrelation with FIG. 3, chips arranged on a frame 44 of the type describedin relation with FIG. 4, of outer dimensions smaller than those of frame34.

FIGS. 5A, 6A, 7A, and 8A are top views, FIGS. 5B, 6B, 7B, and 8Brespectively are cross-section views along planes B-B of FIGS. 5A, 6A,7A, and 8A, and FIG. 5C is a bottom view corresponding to FIG. 5A.

FIGS. 5A, 5B, and 5C illustrate a step during which frames 34 and 44 aresuperposed, and then fastened to each other.

In this example, frame 34 comprises three guide rails 51 a to 51 cpreviously fastened to its lower surface, for example, by welding or bygluing, in the vicinity of three side of the square forming the outercontour of the frame. Guide rails 51 a, 51 b, and 51 c delimit a spaceinside of which frame 44 is capable of being inserted so that frames 34and 44 are superposed, that is, their inner contours have approximatelythe same center in top view. The interval between two guide rails 51 aand 51 c fastened to opposite sides of frame 34 substantiallycorresponds to the outer width of frame 44, and the distance between thecenter of frame 34 and third guide rail 51 b substantially correspondsto half the outer width of frame 44.

A removable lug 53 is capable of being fastened, for example by means ofscrews 55 (three screws in the present example), to the lower surface offrame 34, in the vicinity of the side of frame 34 which is not providedwith a guide rail 51 (on the side of frame 34 opposite to guide rail 51b). For this purpose, tapped holes may have been drilled in frame 34. Asan example, when lug 53 is screwed to frame 34, the interval between lug53 and guide rail 51 b is substantially equal to the outer width offrame 44.

To superpose frame 44 to frame 34, mounting lug 53 is removed and frame44 is inserted between guide rails 51 a, 51 b, and 51 c to have thecenters of the frames coincide (in top view). To lock frame 44 in thisposition, mounting lug 53 is put back in place and screwed to frame 34.At the end of this assembly step, frames 34 and 44 are superposed andfirmly fastened to each other. In this example, the lower surface offrame 34 is placed against the upper surface of frame 44.

Guide rails 51 a to 51 c and mounting lug 53 are provided to remainwithin the outer contour of frame 34. Thus, in top view, the outercontour of the assembly formed by frames 34 and 44 corresponds to theouter contour of frame 34. Such an assembly is compatible withprocessing machines capable of receiving frame 34. It should be notedthat the thickness difference between this assembly and frame 34 aloneposes no problem of compatibility with existing equipment. It willhowever preferably be provided to use a specifically thinned down frame34 so that the thickness of the assembly is as close as possible to thethickness of a standard frame 34.

FIGS. 6A and 6B illustrate a step during which a semiconductor wafer 57is arranged on a surface of an adhesive film 59 stretched on frame 44.The adhesiveness of film 59 allows an easy bonding of the film to theframe and of the wafer to the film. However, if film 59 is not adhesive,it may be provided to bond the film to the frame and/or the wafer to thefilm by means of glue or of any other adapted bonding means. In thisexample, film 59 is bonded on the lower surface side of frame 44.

FIGS. 7A and 7B illustrate the step during which the semiconductor waferis cut into individual chips 58. The cutting is conventionally performedby means of a circular saw (not shown) running through the wafer along agrid of lines and columns. Any other adapted cutting means may howeverbe used. In this example, the cutting is performed across the entirethickness of the wafer and stops in the upper portion of adhesive film59, without however cutting this film.

FIGS. 8A and 8B illustrate a final step where frames 34 and 44 areseparated and frame 34 is removed. To achieve this, removable mountinglug 53 (FIG. 7A) is unscrewed and frame 44 supporting film 59 andindividual chips 58 is removed from the space delimited by guide rails51 a to 51 c (FIG. 7A).

The wafer cut into individual chips 58 can then be shipped to a user onframe 44, for example, for a mounting of chips 58 in electronic devicesby means of equipment which is not compatible with frame 34 but which iscapable of receiving frame 44.

It should be noted that other steps, not shown, for example, inspection,testing and/or marking steps, may be provided between the wafer cutting(FIGS. 7A, 7B) and the separation of the frames (FIGS. 8A, 8B).

An advantage of such a method is that it enables, by a simple operation,to produce, in a manufacturing line specifically adapted to receivingframes of a first type, semiconductor chips arranged on a frame of asecond type having dimensions smaller than those of the frames of thefirst type.

Specific embodiments have been described. Various alterations,modifications and improvements will readily occur to those skilled inthe art.

In particular, a method comprising a step during which a second smallerframe is fastened to a first frame, a step during which a wafer arrangedon the second frame is cut by means of equipment compatible with thefirst frame, and a step of frame separation to use equipment compatiblewith the second frame have been described herein. The present inventionis not limited to this specific case. It will be within the abilities ofthose skilled in the art to implement the provided method in the casewhere the steps of processing, by means of equipment compatible with thefirst frame, of a wafer arranged on the second frame, are steps otherthan the cutting and/or test steps. Further, the present invention isnot limited to the above-mentioned case in which the processing stepsimplemented by means of equipment compatible with the second frame,after separation of the frames, are steps of assembly of the cut chips.

Further, the frames may have any other shape than those shown anddescribed hereabove, provided however for the outer dimensions of thesecond frame to be smaller than the outer dimensions of the first frameand greater than the inner dimensions of the first frame.

Moreover, it will be within the abilities of those skilled in the art toimplement the desired operation by using systems for fastening thesecond frame to the first frame other than the above-described system.It will however be ascertained for the used fastening system to remaincontained within the outer contour of the first frame.

Such alterations, modifications and improvements are intended to be partof this disclosure, and are intended to be within the spirit and thescope of the present invention. Accordingly, the foregoing descriptionis by way of example only and is not intended to be limiting. Thepresent invention is limited only as defined in the following claims andthe equivalents thereto.

What is claimed is:
 1. A method for processing a semiconductor wafer,comprising: fastening a first frame to a second frame; disposing a waferon a film affixed to the second frame; processing the wafer in firstprocessing equipment configured to receive the first frame; removing thefirst frame from the second frame; and processing the wafer in secondprocessing equipment configured to receive the second frame.
 2. A methodfor processing a semiconductor wafer as defined in claim 1, wherein thesecond frame has outer dimensions less than outer dimensions of thefirst frame and greater than inner dimensions of the first frame.
 3. Amethod for processing a semiconductor wafer as defined in claim 1,wherein the film is stretched on the second frame.
 4. A method forprocessing a semiconductor wafer as defined in claim 1, wherein thefirst frame includes at least one fastener element configured to fastenthe second frame to the first frame.
 5. A method for processing asemiconductor wafer as defined in claim 4, wherein the at least onefastener element comprises fastener elements on four sides of the firstframe.
 6. A method for processing a semiconductor wafer as defined inclaim 4, wherein the at least one fastener element comprises guide railson three sides of the first frame and a removable lug on a fourth sideof the first frame.
 7. A method for processing a semiconductor wafer asdefined in claim 6, wherein fastening the first frame to the secondframe comprises removing the removable lug from the first frame,inserting the second frame between the guide rails of the first frameand fastening the removable lug to the first frame.
 8. A method forprocessing a semiconductor wafer as defined in claim 7, wherein removingthe first frame from the second frame comprises removing the removablelug from the first frame and removing the second frame from the guiderails of the first frame.
 9. A method for processing a semiconductorwafer as defined in claim 1, wherein processing a wafer in firstprocessing equipment comprises cutting the wafer into semiconductorchips.
 10. A method for processing a semiconductor wafer as defined inclaim 9, wherein processing the wafer in second processing equipmentcomprises mounting the semiconductor chips in electronic devices.
 11. Asupport frame comprising: a frame body having an outer contour and aninner contour; guide rails secured to the frame body on three sides ofthe inner contour and defining a space for insertion of a single piecesecond frame; and a removable lug secured to the frame body on a fourthside of the inner contour so as to retain the second frame between theguide rails and the removable lug.
 12. A support frame as defined inclaim 11, wherein the guide rails and the removable lug are configuredto fasten a second frame having outer dimensions less than outerdimensions of the frame body and greater than inner dimensions of theframe body.
 13. A support frame as defined in claim 11, wherein theguide rails and the removable lug are mounted to the frame body toreceive a second frame having outer dimensions smaller than outerdimensions of the frame body.
 14. A support frame as defined in claim11, wherein the guide rails and the removable lug are configured toposition the second frame so that a center of the second frame coincideswith a center of the frame body.
 15. A support frame as defined in claim11, wherein the guide rails are secured to the frame body between theinner contour and the outer contour of the frame body.
 16. A supportframe as defined in claim 11, wherein the frame body is configured foruse in first processing equipment and the second frame is configured foruse in second processing equipment.
 17. A support frame as defined inclaim 11, wherein the frame body has a circular inner contour.
 18. Asupport frame as defined in claim 17, wherein the frame body has asquare outer contour with rounded corners.